Field note · 14 January 2026

The three-month rule, and the household it misses

A pamphlet at a bank branch will often say the same thing: keep three months of expenses in cash. The sentence is short enough to remember, and it is the reason so many passbooks in Narathiwat carry a round number that nobody in the household can explain. The trouble is that a household here rarely spends the same amount every month.

Rent may be steady. The market basket is not. A school fee can land in May and again when the next term opens. A fishing household, a rubber smallholding, or a stall that depends on the evening crowd can have a month that is simply quiet. Multiply an average by three and you can bury the May spike inside the average, or you can demand a reserve so large that the household gives up and saves nothing.

Start with the bills that continue

When income stops, some costs stop with it and some do not. Festival food, a new shirt, and a trip to Hat Yai can wait. Rent, rice and the market meals the family still eats, electricity, medicine you already take, a loan instalment, and the fuel that gets someone to work usually cannot. Those are the costs the reserve is for.

Write them for one ordinary month. Use the passbook if you have it, and your memory if you do not. An illustration, not a target: rent 4,500 baht, food 6,000, electricity 800, fuel 1,200, a loan instalment 2,000. That is 14,500 baht of costs that would still be there if the week’s earnings vanished. Your list will be different. The point is that the list belongs to the household, not to the pamphlet.

Then name how long a stoppage usually lasts

Ask when income last failed, and for how long. A stall closed for a week after a family illness is a different reserve from a boat that sat out a rough month. If the usual interruption is two months, the cash target begins at two times the essential monthly figure. The third month in the pamphlet is optional, and it is often the month that makes the target feel impossible.

Add one irregular bill only if it would fall during that stoppage and is not already sitting in its own pot. A school fee that has its own envelope is not added again. A school fee that lives in the same account as everything else will be spent the first time a pump breaks, and then May becomes a second emergency. That separation is the subject of another note on this site. For the reserve itself, keep the figure honest and smaller than a slogan.

What the office writes down

In the Household Emergency Fund Plan we put the essential monthly figure, the number of months, and the baht target on one page. We also name the account or the envelope. A number without a holding place tends to be borrowed for a Saturday purchase and never returned. The contribution is whatever the household can move after payday without missing rice. A modest contribution that happens is worth more than a perfect contribution that is abandoned in the second week.

If you want these figures written for your own household, look at the engagements or arrange a planning meeting.